This invention relates to liquid spray devices, and more particularly, to liquid-atomizing spray guns which employ an AC-oscillator, electromagnet-driven piston pump.
One form of liquid-atomizing spray guns includes an electromagnet having an oscillating armature for driving a piston-pump which draws the liquid from a reservoir and forces the liquid through a spray tip.
Present guns are limited in the electric power they can utilize by various heat dissipation factors. Heat is generated in the electromagnetic coils and must dissipate by flowing through the coil bobbin and insulation tape and then be transferred to air in the housing. A portion of that heat is transferred through the gun housing walls and/or through convection vents in the top and bottom of the housing. The remaining heat is transmitted through the stator of the electromagnet to a heat sink that is cooled by convection of outside air.
It is an object of this invention to provide improved dissipation of heat generated by the electromagnetic coils.
Another object of this invention is to eliminate the heat sink.
A further object is to minimize operator fatigue in the use of the gun.
Yet another object is to reduce the manufacturing cost of the gun.
In piston pump spray guns, a small amount of liquid leaks around the piston. This liquid exits the pump from a collection port and is collected. The leakage flow may be returned to the liquid reservoir for recycling or may be collected in a separate cup or container.
It is another object of this invention to more efficiently recycle the leakage flow without returning the flow to the liquid reservoir.
A further object of the invention is to recycle the leakage flow from a collection cup.
These and other objects of this invention will become apparent from the following disclosure and appended claims.